They say that the definition of insanity is doing the same thing over and over again and expecting a different result. Why is it that the Republicans in Congress seem so determined to prove this maxim

Lets start with the Affordable Care Act, aka Obamacare. The exchanges that are at the heart of Obamacaremaking it possible for people who are currently uninsured to buy health careopen for business on Tuesday. Ever since the Republicans took control of the House, they have held vote after vote to roll back the law, even while ignoring important business like, say, fixing the Postal Service. I think its been 43 times in allvotes that have been utterly pointless, in that the Senate is still run by Democrats, and the law is President Obamas signature achievement, and theres no way on Gods green earth it will be repealed.

But never mind. As October 1 has nearedthe date both Obamacare kicks in and the government needs to be fundedRepublicans moved to another tactic, which was every bit as hopeless. They began demanding that Obamacare be reversedor at least delayed as part of any deal to keep the government running. (At one point they had a lengthy wish list that was so implausible it was almost laugh-out-loud funny.)

But to the surprise of absolutely no one, when Republicans added the anti-Obamacare language to the continuing resolution designed to finance the government (for all of six weeks!), the Senate quickly rejected the House bill and insisted instead on a continuing resolution that did nothing but what it was supposed to do: fund the government. Republicans, meanwhile, would not back away from their demand that the CR had to be linked to a delay in Obamacare.

I see almost no hope of avoiding a government shutdown, Representative Jim Cooper, a conservative Democrat from Nashville, told me Monday afternoon. Its possible, of course, that House Republicans will pass a continuing resolution in the wee small hours, after this column has gone to bed. But its very unlikely.

And thats the second way in which Republican strategy seems to have run off the rails. This constant brinkmanship, which Republicans bring on with their unrealistic demands and deadlines, consistently redounds against them. It makes you wonder what they are trying to accomplish.

But, of course, we know what they are trying to accomplish. They are trying to mollify the extremist element of their party, the Tea Party Republicans who vote in primaries and who have succeeded in electing lots of House members and a handful of senators, such as Ted Cruz of Texas and Marco Rubio of Florida.

The House speaker, John Boehner, wont bring a clean CRthat is, a continuing resolution without any of the anti-Obamacare languagenot because it wont pass, but because it probably would, which would infuriate the Tea Party wing of his party and jeopardise his leadership post. Indeed, as Boehner well knows, many House Republicans do not want the government to shut down and would probably vote for the Senates clean bill if given half a chance. Their unwillingness to speak out against the extreme faction in their party is shameful. And its tragic that, at a time when the House desperately needs a strong speaker, it has John Boehner instead.

What was clear on Monday was that if the government does shut down, the Republicans are going to be blamed. All day long, we watched the Democrats, starting with President Obama, make the case that Republican demands were unreasonable, and, indeed, dangerous, given what was at stake. Republicans spent the day on the defensive. Senator Elizabeth Warren, the liberal Democrat from Massachusetts, described Republican tactics to me as hostage taking. Harry Reid, the Senate majority leader, told reporters that if we cant pass thismeaning a clean CRwere only truly entering a banana republican mind-set.

I hate the fact that I now know what a clean CR means. Its the kind of inside-the-Beltway term that the country only learns about when there is some big crisis in Washington, as there is now. A government that functioned would fight over the budget but would ultimately pass a budget. This government can barely hobble from one CR to the next.

A party controlled by its most extreme faction will ultimately be forced back to the center. The Democrats learned that when Walter Mondale was losing to Ronald Reagan, and Michael Dukakis to George H W Bush. Now it is the Republicans who dont seem to understand that their extreme tactics are pleasing a small percentage of their countrymen but alienating everyone else.